Super Jet trouble with stripping driveshaft splines on lenzi hull

[scootinhooten]

I'm away from home again until Saturday to check if the pump is set back but maybe I need to run a longer midshaft?? Christian says his ski has a 2" setback motorsuperjetjim says motor cant be set backI'm thinking if you set your pump back you would need to do the same to engine location to keep everything engaged (motor-mid-driveshaft)

 

[scootinhooten]

Oooops motoman not supetjetjim

 

[tomski]

What driveshaft are you using? When you arrive home, show a picture of the pump and how much the driveshaft extends past the bulkhead.

 

[Matt_E]

If that's my old 140 setback them the original shaft was a mint Jetmaniac sb shaft

 

[matth113]

Does the midshaft have 20mm of shaft out the back of it ?

 

[Christian_83]

Hmm why cant a motor be set back??
Please tell me this, as my motor are moved farther back in the engine bay, than a stock. AND i need to run a GP800/WR1100 midshaft, that is shorter (122mm vs normal 160mm)
Look a this pics and tell me my engine is not setback

 

[JetManiac]

Hmm why cant a motor be set back??
Please tell me this, as my motor are moved farther back in the engine bay, than a stock. AND i need to run a GP800/WR1100 midshaft, that is shorter (122mm vs normal 160mm)
Look a this pics and tell me my engine is not setback

View attachment 187532View attachment 187533

That midshaft also has the splines a in different location relative to the shaft when compared to the SJ midshaft. I believe some BOBs also use that setup.

 

[fastony]

What Chris said..

Also - if you have stripped your drive shaft your intermediite will be toast as well - you need to replace both at the same time or one will just eat the other due to poor engagement.

X2
When you lost the splines on the first shaft it took out the splines on the mid shaft, replace them both and come ride with us. You can take the ones out of Justins ski he's not riding much! lol

 

[Christian_83]

Chris - correct, the splines on thoese midshaft sits in the far back end of the shaft, i think splines end allmost were the threads end. And the oem 160mm shaft have the splines in the first part of the shaft.

 

[scootinhooten]

Driving home from West Texas now ill have more pics and info tomorrow ......Matt_E ; this ski came from Webster ny.... if this is one you've had do you know what mid/driveshaft combo it needs

 

[motoman96]

If that's my old 140 setback them the original shaft was a mint Jetmaniac sb shaft

It's not, I just put that pump in a sj yesterday.lol

 

[scootinhooten]

 

[scootinhooten]

Found the problems
alignment on pump side was way off.... I can shim and fix that.
and the driveshaft midshaft are not getting enough spline engagement.... how should I go about fixing this?

 

[JetManiac]

Found the problems
alignment on pump side was way off.... I can shim and fix that.
and the driveshaft midshaft are not getting enough spline engagement.... how should I go about fixing this?

Sometimes you can press the midshaft back far enough to get proper overlap. In your case, however, the midshaft looks like it is already pressed to factory spec (19.5-20.5mm) or far enough that the additional amount that you need to press it wont be possible without modifying the shaft. The outside front of the midshaft probably needs to be machined to allow the shaft to be pressed far back enough through the bearing to correct your alignment.

The shorty GP midshafts discussed earlier in your thread would make the too short driveshaft problem worse.

You can have a custom length driveshaft made to correct the problem.

Unless someone else has other ideas?